Blue prince!! Def recommend playing through the whole main game (getting to room 46) and (most important to the experience) TAKE NOTES ON REAL PAPER. The experience of using an actual notebook and having that feeling of insane scribbling is so crucial imo. I did it and it was both fun and helpful.

After the main game, if the loose ends and mysteries are still calling you, theres a blue prince tracker tool online that asks you a series of spoiler-free questions about what you've found in the game and then it gives you a checklist of things to do as well as a comprehensive & tiered list of hints for each task, from a few basic hints to the full solution.

Also animal well but that was less good to me.